Open cell or Closed cell Spray foam

[FarmerSid]

My basement flooded a few weeks ago and am ready to put things back together. I'm down to bare 2X4 studs walls 1/2" away from the block exterior walls and all insulation removed from the walls and joist cavities. I think I'm going to spray foam the walls from floor to ceiling and the joist cavities. After reading about spray foam and what the contractors use according to their ads in the yellow pages, I'm down right cornfused!! They use Icynene, polyurethane or Urethane.

Anybody care to explain to me what I should be using in my basement redo.

Thanks!! Muchly appreciated!

 

[siddle]

Before I suggest you anything, you should know the local code requirements related to r-value, ignition barriers and permeability when selecting between an open or closed cell product.

 

[milner351]

For sure check out codes before you proceed.

I have icynene foam - sprayed directly against the bottom of the metal roof of my pole barn.

Icynen I believe is referred to as open cell - water, and water vapor will go through it (I have some roof leaks I'm having a hard time finding)
it's MUCH lighter than urethane foams and does not get HARD like they do. It's a very good sound insulator as well.

 

[FarmerSid]

Thanks for the replies. Minimum code in my area is R13. Either foam has to be covered with a fire barrier. 1/2" drywall will pass. Depending on what foam is used will determine if a vapor barrier is needed. Is this the info you are looking for Siddle?

 

[dlenkewich]

Most people would suggest the closed cell foam. To my knowledge it's a polyurethane coating.

Although I'm hardly an advocate for any spray foam, atleast with closed cell you spray it and forget it. Going with open cell foam and still having to vapour barrier it isn't cost or time efficient.

 

[dirttracker18]

Some thoughts as I have been researching spray foam to prepare for fixing my cathedral ceiling this summer.

A couple of consideration for a basement application.

If open cell is cheaper then putting up a VB is cheap and easy. This would save money. However, in spraying the open cell foam on the block and then having a VB on the wall you open up an area where moisture can/will build up between the VB and the foam (the cavity between the VB and the foam). This will happen as the open cell foam can allow moisture through it. This may be negligible but would be a concern for me. You do not want moisture sitting on the wood walls and creating mould.

On the other hand if you use a closed cell this is no longer a concern as the it acts as your VB and then the cavity between your drywall and the foam can breath and release moisture. Very little should get in there as it is part of the condition area of the home now.

Some stuff to think about that comes to mind.

I am not an expert or in the industry. I have jsut had a lot of time to think about spray foam in the past year to prepare for this summer

 

[dlenkewich]

Some thoughts as I have been researching spray foam to prepare for fixing my cathedral ceiling this summer.

A couple of consideration for a basement application.

If open cell is cheaper then putting up a VB is cheap and easy. This would save money. However, in spraying the open cell foam on the block and then having a VB on the wall you open up an area where moisture can/will build up between the VB and the foam (the cavity between the VB and the foam). This will happen as the open cell foam can allow moisture through it. This may be negligible but would be a concern for me. You do not want moisture sitting on the wood walls and creating mould.

On the other hand if you use a closed cell this is no longer a concern as the it acts as your VB and then the cavity between your drywall and the foam can breath and release moisture. Very little should get in there as it is part of the condition area of the home now.

Some stuff to think about that comes to mind.

I am not an expert or in the industry. I have jsut had a lot of time to think about spray foam in the past year to prepare for this summer

There likely wouldnt be any gaps. The method with open cell is to hit every other cavity, saw off the excess and leaving the cavity completely full. Closed cell is only typically sprayed on a few inches thick.

 

[Zick]

FYI
Closed cell has a lot higher r-value compared to open cell but the price goes along with it.

We did our entire house with closed cell but to cut down on cost, we only did an 1 1/2" spray and then R13 over top it in a 6" wall.
This helped create a very air tight seal that was also well insulated at a resonable cost.

 

[willymakeit]

Open cell is basicaly the same as a sponge. It will hold water.

 

[FarmerSid]

Thanks all! I kinda thought either type had it's place in a house. Seems open is used above grade and closed below. Still gotta do some reading.

 

[burleymike]

Here is a link explaining it best. You want open cell so moisture will not be trapped behind the insulation which would then keep your walls saturated. In this document they talk about rigid foam insulation but same thing with spray foam.

http://www.buildingscience.com/documents/reports/rr-0202-basement-insulation-systems

 

[catuck]

Burleymike - are you sure about that? I'm very familiar with that article, and they recommend XPS or EPS rigid insulation, both are closed cell. It would be helpful if they would update it for spray foam. I'm not sure which is correct but my feeling is closed cell is the right choice.

 

[kb2tha]

My research on this topic determined that closed cell is only effective as a VB in thicknesses of 3" or more. Prices here: open cell $.35/SF/inch and closed cell $.85/SF/inch.

In my garage I used open cell on walls. 3" covered with 1" rigid urethane (R7), 6 mil poly and 1/2 sheetrock. Ceiling R49 blown FG. 5/8" FC sheetrock, no VB with plenty of venting.

Ken

 

[FarmerSid]

Well, I have had three different spray foam contractors come out, tell me what they would do and give me a price. All three were great to talk to and never once tried to sell me more than I needed. If anything, I'd like to put the foam on thicker! One contractor that came out monday night uses a 0.5 lb open cell foam and would fill the cavity comepletely (3.5" +1/2" space between stud and blocks) and trim it flush to the stud to an R15. The two contractors that came out last night both use BASF Walltite ECO which for those that don't know is a medium density polyurethane 2lb closed cell foam. They would spray on 3". All the contractors that I called that uses closed cell said that a minimum of 2" is needed to eliminate the vapor barrier.

So I think my decision is made. Spray foam it is! Now I have to get my but in gear and get the walls correctly installed and wiring done. They can come as soon as next monday to spray. Should take about 6 hrs to spray. Knowing people, beer and CASH made a huge difference in prices. Looking forward to a warmer basement next winter.

Now I have to look into what type of flooring to put down. I only have 7' of headroom between the cement floor and the floor joists.

 

[catuck]

So - did you decide on open or closed? If open, do not use a vapor barrier between insulation and drywall - it will trap moisture.

 

[milner351]

Tile is a natural over a concrete floor in a basement - however if you want a "warm floor" look into the floating floors you can put carpet over - the ones i've seen would only ad about an inch to the floor height.

 

[FarmerSid]

Sorry catuck! Going to use the Walltite ECO closed cell foam. Not sure I agree with no vapor barrier with open cell. IMHO, vapor can go through open cell and then hit the drywall. I agree with you on closed cell though.

I found a product called Tyroc. (http://www.tyrocinc.com/home.html) What I like about it is that it's only 1/2" thick which would be nice in my low headroom area. Pretty much the same price as Dricore type floor systems. In my area they are $8.99 per sheet (16"X48"X1/2") A little pricey but what else can I do? Just underlay and carpet over the cement?

 

[theoldwizard1]

... open cell - water, and water vapor will go through it ...

Sponges are open cell. They hold water quite well. But they will "dry out" fast if they have good air flow around it.

Closed cell foam is not 100% waterproof. Once water penetrates it, is takes forever to dry out, even when exposed to good air flow,

 

[catuck]

Not sure I agree with no vapor barrier with open cell. IMHO, vapor can go through open cell and then hit the drywall. QUOTE]

If moisture goes through the open cell foam, it must exit to the interior of the basement. If it is stopped by a vapor barrier, it has no place to go and will propagate mold. Drywall is permeabe so it will pass into the basement.

Happy to hear you're going with closed cell - it's a great product.